JP2588348B2 - Variable shape actuator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a variable-shape actuator capable of flexible movement, and more particularly, to a thin-plate-shaped object or a small-sized object by moving an output unit while keeping it parallel to a support unit. The present invention relates to a shape-variable actuator that can be gripped by a user.

[0002]

2. Description of the Related Art In a semiconductor manufacturing process, when a mechanical shock is applied to a wafer, an internal defect is generated, which may affect its electrical characteristics. Further, particles necessarily generated by such mechanical shock may be larger than the fine circuit elements to be formed on the wafer, and thus hinder necessary fine circuit processing. For these reasons, mechanical shock should be eliminated as much as possible in semiconductor manufacturing. However, conventionally, a mechanical movement element in an actuator such as a motor or a piston mechanism generally has a rigid structure, and is configured to have a movement on the order of microns and positioning accuracy by the rigidity. If such a rigid motion element hits another member or the like while performing a predetermined motion, a mechanical impact will be generated. Hereinafter, this is called a hard movement. Therefore, when such a hard movement is used for the wafer transfer or the like in the semiconductor manufacturing process, extremely precise position control and speed control need to be performed to suppress the occurrence of mechanical shock.

On the other hand, as seen in current robot driving, an actuator used under the integrated control by a microprocessor using a developed visual and tactile sensor is not necessarily a rigid structure and has a high machining accuracy. Not only those having Rather, it is expected that the use of a flexible actuator capable of flexible movement under such general control will lead to the development of artificial fingers that can replace human fingers. Therefore, it is considered that such a flexible-moving actuator can realize a shock-free transport mechanism applicable to a semiconductor manufacturing process under much simpler control than a hard-moving actuator.

Therefore, some proposals have been made as flexible actuators to be applied to such applications. For example, as a first example, the inside of a rubber tube is divided into three chambers in the circumferential direction to form an aggregate of three pressure chambers that are long in the axial direction. Various types of flexible deformation such as extension in the axial direction and torsion around the axis are known. (Suzumori, Transactions of the Japan Society of Mechanical Engineers, C Edition (Hei 1-10), 2547-25
52)

[0005] Alternatively, as a second example, a reinforcing fiber (peripheral reinforcing fiber) 33 is densely wound around a rubber tube 32, and another reinforcing fiber (axial reinforcing fiber) 34 is joined along the axial direction ( FIG. 12). When the circumferential reinforcing fibers 33 are pressurized in the rubber tube, they have an effect of preventing the diameter of the rubber winding from expanding and expanding only in the axial direction. And the shaft reinforcing fiber 34
When the actuator is pressurized, the portion where the shaft reinforcing fiber 34 is not provided expands, and as a whole, the shaft reinforcing fiber 34 is curved inward. (FIG. 13). (Tanaka, Mechanical Design 36, 8 (1992-7), 32-39) If these flexible actuators are applied to a wafer transfer device of a semiconductor manufacturing device, there is no risk of generating internal defects or particles due to mechanical shock. It is expected that an excellent wafer transfer mechanism will be realized.

[0006]

However, each of the above-mentioned flexible actuators has various problems. Although the first actuator can perform various operations by itself, it is not easy to manufacture a rubber tube divided into three in the circumferential direction, and it is disadvantageous in cost. In particular, it is difficult to realize a small-diameter long one. Further, there is a drawback that compressed air of three types of pressure is required for use. Furthermore, an extremely complicated three-dimensional analysis is required to analyze the actual deformation behavior of the tube based on the shape of the three chambers and the supply pressure. Therefore, advanced analysis technology using, for example, the finite element method is required for pipe design and drive pressure design, and the burden on use is large.

In the second actuator, this problem has been solved. One end is fixed, and the non-fixed end is used as an output end. But,
Since the entire actuator moves in a curved manner, both the position and the angle of the non-fixed end, which is the output end, change as shown in FIG. Therefore, when trying to grip a thin plate-like object such as a silicon wafer with this actuator, the contact between the actuator and the object becomes a point contact, and the grip is not stable. In this case, the displacement of the output end of the actuator in the axial direction, that is, in the horizontal direction in the drawing, is substantially large in proportion to the overall length of the actuator, so that it is not easy to set the actuator mounting position with respect to the position of the object to be grasped. In particular, it is difficult to grip a small object. 12 and FIG.
In the case of fixed at one end, vibration is generated depending on the weight of the object and the position accuracy is deteriorated. Therefore, it is preferable to fix both ends. Can not do.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an output portion is provided on a tube shaft without changing the angle and with a minimum displacement in the tube axis direction. By displacing in the direction perpendicular to the object, it is possible to securely grip a thin plate-shaped object, and it is easy to set the mounting position of the actuator with respect to the object and to easily grip a small object. An object of the present invention is to provide a variable shape actuator suitable for a field. It is also an object of the present invention to provide a variable shape actuator which is fixed at both ends of a tube, grips an object at the center of the actuator, generates less vibration due to the weight of the object, has good positional accuracy, and is suitable for the semiconductor manufacturing field. Aim.

[0009]

In order to achieve the above-mentioned object, a variable-shape actuator according to the present invention comprises a flexible tube, a circumferential reinforcing fiber wound around the tube, and joined to the tube. A variable axis actuator having a shaft reinforcing fiber, wherein the first shaft reinforcing fiber is joined around the circumference of the tube from a start end to an end at a position 180 ° opposite to the start end around a half circumference; The shaft-reinforcing fiber is joined to the opposite side of the first shaft-reinforcing fiber from the beginning to the end of the first shaft-reinforcing fiber. Or
The shape-variable actuator of the present invention includes a plurality of sets of the shaft-reinforcing fibers, wherein the position of the starting end of each shaft-reinforcing fiber is on the same straight line with respect to the axial direction of the tube. Is done. Alternatively, the variable-shape actuator of the present invention has the above-mentioned configuration, wherein both ends are fixed.

[0010]

In the variable-shape actuator of the present invention having the above-mentioned structure, when air pressure is applied to the inside of the tube, the expansion and contraction of the tube is partially restricted by the reinforcing fibers bonded to the tube. , The output end is displaced without changing the angle. When the applied pressure is released, the tube returns to a linear state. With such a movement,
The thin plate-shaped object can be gripped flexibly and reliably. In an actuator with fixed ends, when air pressure is applied to the tube, the center of the actuator is displaced. When the applied pressure is released, the tube returns to a linear state. By such movement, the plate-like object can be grasped flexibly and reliably.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment embodying a variable shape actuator according to the present invention will be described below with reference to the drawings. FIG. 1 (a)
FIG. 2 is a configuration diagram of the variable shape actuator of the present embodiment.
The actuator 1 shown in FIG. 1A is obtained by joining reinforcing fibers to a flexible tube 2 with an adhesive. There are two types of such reinforcing fibers, those that are perpendicular to the axial direction of the tube 2 and those that are not perpendicular to the axial direction. The circumferential reinforcing fibers 3 perpendicular to the axial direction are tightly wound around the entire length of the tube 2 and have a function of restricting the radial expansion and contraction of the tube 2.

The tube 2 has an axial reinforcing fiber 4 bonded thereto. Here, the joining position of the shaft reinforcing fiber 4 is the starting end 5.
As shown in the perspective view of FIG. 1 (b), in which the peripheral reinforcing fibers 3 are omitted, the first shaft reinforcing fibers are provided on the front side of the tube 2 as shown in FIG. A certain first
A branch and a second branch which is a second axial reinforcing fiber are joined to the back side. In FIG. 1A, the first branch and the second branch are overlapped. The axial reinforcing fiber 4 has a function of restricting the elongation and contraction of the tube 2 at the position where the shaft reinforcing fiber 4 is joined, and a function of restricting the bending of the tube 2 in a direction perpendicular to the intended deformation in the radial direction. have.
One end of the actuator 1 is fixedly attached to the tube holder 6, and is connected to a compressed air cylinder 9 via a pressure supply hose 12. The shutoff valve 10 interrupts the supply of the compressed air from the compressed air cylinder 9 to the actuator 1, and the release valve 11 releases the compressed air supplied to the actuator 1 to the atmosphere to return the actuator 1 to a natural state. Things.

The actuator 1 having the above configuration is
When it is in a natural state, that is, when the inside of the tube 2 is at atmospheric pressure, the tube 2 has a linear shape as shown in FIG.
When the open valve 11 is closed and the shutoff valve 10 is opened, compressed air is supplied from the compressed air cylinder 9 and the inside of the tube 2 is pressurized. At this time, the flexible tube 2 tends to expand in its entirety, but exhibits a unique movement because the extension is partially restricted by the reinforcing fibers to be joined. That is, since the elongation in the radial direction is regulated by the circumferential reinforcing fibers 3 wound over the entire length, the tube 2 mainly tends to elongate in the axial direction. However, the portion where the axial reinforcement is restricted by the axial reinforcing fiber 4 exists in an elliptical shape. At a portion where the axial reinforcing fibers 4 are not bonded, the axial elongation is not restricted.

For this reason, the actuator 1 deforms in an S-shape showing the rotation of the shaft reinforcing fiber 4 as a radius, and the output end 8 moves upward in the figure as shown in FIG. Since the deformation of the actuator 1 at this time is symmetric with respect to the center point, the inclination of the actuator 1 at the output end 8 is canceled out to be 0 °. Shut off valve 10 and open valve 11
Is opened, the inside of the tube 2 becomes atmospheric pressure, and FIG.
The state returns to the linear state of FIG.

Consider the movement of the output end 8 of the actuator 1 at this time. Since the change in the angle, that is, the inclination, of the movement of the output end 8 is 0 ° as described above, the objects to be considered are the displacements in the x direction and the y direction in the drawing.
Considering that the actuator 1 actually grips an object, what is important is whether or not to obtain the necessary y displacement.
That is, there is little displacement.

Therefore, it is desirable to represent the x displacement as a function of the y displacement. X displacement of actuator 1 is x ₁
, And y displacement is y ₁ (see FIG. 3, FIG. 3 is a view for explaining the movement of the actuator 1, and the peripheral reinforcing fibers 3 are omitted), and x ₁ = y ₁ * (cos α ₂ − cos α ₁ ) / (sin α ₂ −sin α ₁ ) (1) Here, α ₁ means the angle formed by the axial reinforcing fiber 4 of the actuator 1 in a non-pressurized state with respect to the axial direction of the tube 2 (horizontal direction in the drawing), and α ₂ denotes the actuator 1 in the pressurized state. Is the angle formed by the axial reinforcing fiber 4 with respect to the horizontal direction in the figure. Therefore, α ₁ is a negative value.

For comparison, FIG. 14 shows the movement of the conventional actuator without the peripheral reinforcing fibers 33. In FIG. 14, assuming that x displacement is x ₂ and y displacement is y ₂ , x ₂ = (y ₂ * sin α ₃ ) / (1−cos α ₃ ) −L (2) Where L is the total length of the actuator, α ₃
Indicates the tilt angle at the output end in FIG. Note that the entire actuator is uniformly curved in an arc shape. Here, representative numerical values are substituted into the expressions (1) and (2), and the two are compared. First, in both cases, the length of the actuator is 10 cm, and the diameter D is 1 cm. Further, the required y displacement is 4 cm. Therefore, L = 10c
m, y ₁ = y ₂ = 4 cm.

Thus, the actuator 1 of this embodiment
Α ₁ and α _{2 at} are obtained. α ₁ is an angle formed by the axial reinforcing fiber 4 of the actuator 1 with respect to the axial direction of the tube 2 when not pressurized, and has a negative value here, so tan α ₁ = − (1 cm) / (10 cm) = −0.1, and α ₁ = −0.0997 (rad) (= −5.71 °) (3) is obtained.

On the other hand, α ₂ is sin α ₂ = (y ₁ −D) / R ₁ (R ₁ is the length of the axial reinforcing fiber 4 in the figure). Since R ₁ = L / cos α ₁ , R ₁ = (10 cm) / cos (-0.0997 (ra
d)) = 10.1 (cm), sin α ₂ = (4 cm−1 cm) / (10.1 cm) = 0.297, and α ₂ = 0.302 (rad) (= 17.3 °) (4) ) Is obtained.

Then, in the conventional actuator, α
_3, holds the relationship between _{R 2 α 3 = L (5} ) between the L from FIG. Here, R ₂ is the radius of curvature of the actuator curved in an arc shape. Further, from FIG. 14, the relationship of y ₂ = R ₂ −R ₂ cos α ₃ (6) can be read. Here, L = 10c
m, since it is _{y 2 = 4cm, R 2 α} 3 = 10 (cm) (7) R 2 -R 2 cosα 3 = 4 (cm) (8) next, R _2, α ₃ satisfying this, R ₂ = 11.8 (cm) (9) α ₃ = 0.85 (rad) (= 48.7 °) (10)

Therefore, the equations (3) and (4) are substituted into the equation (1), and since y ₁ = 4 cm, x ₁ = −0.40 cm is obtained. On the other hand, the equation (10) is substituted into the equation (2), and since L = 10 cm and y ₂ = 4 cm, x ₂ = −1.16 cm is obtained. As described above, the x displacement x ₁ in the actuator 1 of this embodiment is x
Small it can be seen than the displacement x _2.

Therefore, for example, a diameter 1 placed on a flat plate
Considering a case where a small object of about mm is to be grasped, two sets of actuators are transported to the vicinity of the object, and the needle-shaped object is pinched by causing the actuator to bend and deform. At this time, in the conventional actuator, the above-mentioned x displacement is equal to or larger than the size of the object, and the tip of the actuator is inclined to make point contact with the object, so that it is difficult to hold the object. On the other hand, in the actuator 1 of the present embodiment, as described above, the x displacement is small and the tip of the actuator 1 does not tilt, so that point contact does not occur with the object, and the small object is securely clamped. be able to. As described above, in the actuator 1 of the present embodiment, as compared with the conventional actuator, the setting of the actuator mounting position with respect to the position of the object to be grasped is easy, and the small object can be easily grasped. Suitable for the semiconductor manufacturing field.

Next, a second embodiment of the present invention will be described with reference to FIG.
It will be described based on. FIG. 4 is a configuration diagram of the variable shape actuator of the present embodiment. The actuator 20 shown in FIG. 4 is an actuator having substantially the same configuration as the actuator 1 of FIG. 1, in which a circumferential reinforcing fiber 22 is bonded to a flexible tube 21 by an adhesive. Supply of compressed air from a compressed air cylinder 37 via a pressure supply hose 36 and a shutoff valve 38;
, The compressed air can be released in the same manner as the actuator 1. The difference from the actuator 1 is that two shaft reinforcing fibers 23 and 24 are joined, and both ends are fixed by a tube holder 26 and a tube holder 27. And the starting end 28 of the shaft reinforcing fiber 23
The starting end 31 of the shaft reinforcing fiber 24 is coaxial with the tube 21, and the terminal end 29 of the shaft reinforcing fiber 23 and the terminal end 30 of the shaft reinforcing fiber 24 are coaxial with the tube 21.

The actuator 20 having such a configuration
When the shut-off valve 38 is opened and compressed air is supplied from the compressed air cylinder 37, the left half of the actuator 20 in the figure shows the same deformation as the actuator 1, and the right half shows the deformation symmetric with the actuator 1. 5, the central portion of the actuator 20 moves upward in the figure. When the shutoff valve 38 is closed and the release valve 35 is opened, the compressed air is released and the actuator 20 returns to the linear state of FIG.

In the actuator 20, the target object is gripped at the central portion which moves up and down. Since both ends are fixed by the tube holder 26 and the tube holder 27, vibration occurs due to the weight of the target object to be gripped. Is reduced, and the position accuracy is improved. Further, as an effect of fixing both ends, there is also an effect that the joining position of the shaft reinforcing fiber 23 and the shaft reinforcing fiber 24 does not have to be so strict. Further, another actuator 20 can be arranged at the end of the tube holder 27 in FIG. 4 and can be operated simultaneously. At this time, it can be said that the actuator 20 has both the function as an actuator and the function as a pipe.

Furthermore, if three or more actuators 20 are arranged in a ring and operated simultaneously, a plate-like object (for example, a silicon wafer) placed at the center of the ring can be gripped, and the semiconductor manufacturing field can be increased. Are suitable. For example, FIG. 6 shows a wafer holding device 60 realized by arranging four actuators 20 in a ring shape. In the wafer holding device 60, four tube holders 64
Both ends of one actuator 20 are fixed. When pressurized from the common pressurizing port 61, the wafer holding device 60
As shown in (4), the four actuators 20 are simultaneously deformed, and the wafer clip 63 attached to the center of each actuator 20 grips the wafer 62. By transferring the wafer holding device 60 holding the wafer 62, the wafer 62 can be moved from the semiconductor manufacturing apparatus to another semiconductor manufacturing apparatus.

Further, an example in which the actuator of each embodiment described above is modified will be described. FIG. 8 shows that FIG.
The actuator 40 is a modification of the actuator 1 of FIG. The actuator 40 is formed by joining two shaft reinforcing fibers, a shaft reinforcing fiber 41 and a shaft reinforcing fiber 42, to the tube 2, and the other configuration is the same as that of the actuator 1.
When the actuator 40 is pressurized, the actuator 40 takes a shape as shown in FIG. 9, and similarly to the case of the actuator 1, the output end 43 is displaced from the state of FIG. 8 without changing the angle, and is parallel to the axial direction of the tube 2. Displacement in various directions is also small. Therefore, similarly to the actuator 1, the thin plate-shaped object can be surely grasped by the actuator 40, the position of the actuator 40 with respect to the object can be easily set, and the small object can be easily grasped. Further, three or more axial reinforcing fibers may be used.

FIG. 10 shows an actuator 50 obtained by modifying the actuator 20 shown in FIG. The actuator 50 is formed by joining four shaft reinforcing fibers of a shaft reinforcing fiber 51, a shaft reinforcing fiber 52, a shaft reinforcing fiber 53, and a shaft reinforcing fiber 54 to the tube 21, and the other configuration is the same as that of the actuator 20. . When the actuator 50 is pressurized, the actuator 50 takes a shape as shown in FIG. 11, and the central portion moves upward in the figure as in the case of the actuator 20. Therefore, the actuator 50 is also the actuator 2
As in the case of 0, the target object is gripped at the center and the vibration due to the weight of the target object is small, so that the positional accuracy is good. The number of axial reinforcing fibers may be further increased. Further, the actuator 50 can also function as a pipe, and two or more actuators 50 can be simultaneously operated.

In the actuators of the above embodiments, for example, silicone rubber,
Raw rubber or the like is conceivable, but is not limited thereto, and any material having appropriate flexibility and elasticity may be used. In addition, as the material of the peripheral reinforcing fiber and the shaft reinforcing fiber, in addition to metal and carbon fiber, silk thread may be used, but the tube and the adhesive are well compatible, and the flexibility is high only in the operation direction and in the non-operation direction. You should choose one that is less flexible. It is preferable to use an adhesive of the same quality as the tube as an adhesive for joining them. The embodiments do not limit the present invention, and various modifications and improvements can be made without departing from the spirit of the present invention.

[0030]

As is apparent from the above description, in the actuator of the present invention, the starting end and the end of the shaft reinforcing fiber to be joined to the tube are opposed to each other by 180 °, and the first and second ends of the tube are provided on both sides of the tube. The shaft reinforcing fiber and the second shaft reinforcing fiber are joined to each other, so that the output end of the tube shaft does not change its angle and minimizes displacement in the tube axis direction. Displace in the direction perpendicular to. This makes it possible to securely grip the thin plate-shaped object, to easily set the mounting position of the actuator with respect to the object, and to easily grip a small object. In addition, since there are two or more sets of axial reinforcing fibers, the starting end and the end of which are on the same axis of the tube, and both ends of the tube are fixed, the object is located at the center of the actuator. Grasping and vibration due to the weight of the target object are small, and positional accuracy can be improved. Thus, a variable shape actuator suitable for the semiconductor manufacturing field can be provided.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a variable shape actuator which is an embodiment of the present invention.

FIG. 2 is a view showing the movement of the actuator shown in FIG. 1;

FIG. 3 is a view showing the movement of the actuator shown in FIG. 1;

FIG. 4 is a diagram showing a configuration of a variable shape actuator which is an embodiment of the present invention.

FIG. 5 is a view showing the movement of the actuator shown in FIG. 4;

FIG. 6 is a diagram showing a configuration of a wafer holding device by a combination of actuators shown in FIG. 4;

FIG. 7 is a view showing the movement of the wafer holding device shown in FIG. 6;

FIG. 8 is a view showing a configuration of a variable shape actuator which is an embodiment of the present invention.

FIG. 9 is a view showing the movement of the actuator shown in FIG. 8;

FIG. 10 is a view showing a configuration of a variable shape actuator which is an embodiment of the present invention.

FIG. 11 is a view showing the movement of the actuator shown in FIG. 10;

FIG. 12 is a diagram showing a configuration of a conventional variable shape actuator.

FIG. 13 is a view showing the movement of the actuator shown in FIG.

FIG. 14 is a diagram showing the movement of the actuator shown in FIG.

[Explanation of symbols]

 1,20 Shape variable actuator 2,21 Tube 3,22 Circumferential reinforcing fiber 4,23,24 Axial reinforcing fiber 6,26,27 Tube holder

Claims (3)

(57) [Claims] 1. A variable shape actuator comprising: a flexible tube; a circumferential reinforcing fiber wound around the tube; and a shaft reinforcing fiber bonded to the tube; Is joined around the circumference of the tube halfway from the start end to the end at a position 180 ° opposite to the start end, and the second axial reinforcing fiber is the first from the start end to the end of the first axial reinforcing fiber. The shape variable actuator characterized by being joined to the opposite side of the axial reinforcing fiber. 2. It has a plurality of sets of the axial reinforcing fibers,
2. The variable shape actuator according to claim 1, wherein the position of the starting end of each axial reinforcing fiber is on the same straight line with respect to the axial direction of the tube. 3. The variable shape actuator according to claim 2, wherein both ends are fixed.